This invention pertains generally to the art of transport refrigeration units and in particular to that part of the art relating to component and structural arrangements for such units.
As stated in applicants' assignee's U.S. Pat. No. 4,182,134, there are a number of obviously desirable characteristics which those in the business of manufacturing transport refrigeration units would like their units to have. As noted in that patent, some of these characteristics are a relatively small projection of the unit into the transport trailer, easy access for maintenance and service, manufacturability, light weight while having adequate structural strength and adequate refrigerant capacity for the intended service. The commercial unit according to that patent is considered to have those characteristics, but further improvements in component and structural arrangements are not precluded if a fresh look is taken at the desirable characteristics. The present invention is intended to provide a component and structural arrangement for such a unit which provides further improvements over those of the noted patent.
Among the improvements obtained with a design according to the invention is a better trailer interior airflow pattern compared to the present commercial unit. Also, the parts are so arranged as to simplify the blower drive arrangement through eliminating drive belt twists, and simplifying the belt tensioning arrangement. Another improvement is locating the evaporator and condenser coils close to the main support frame of the unit to permit a reduction in support material and unit weight. The overall packaging arrangement reduces the unit width about 5 inches relative to the commercial art predecessor, and also provides a smaller swing radius (the radius required to avoid the truck tractor from contacting the transport refrigeration unit as the tractor turns relative to the trailer, Finally, the design permits an electric standby motor option in which the motor is located within the confines of the cover and without requiring an add-on motor support tray under the unit, which is typical of the unit according to the patent.